Machinery for separating sand



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sTATEs PATENT oiEEIcE.

WILLIAM BISHOP, OF COVENTRY, CONNECTICUT.

MACHINERY FOR SEPARATING SAND, &c., FROM PULP IN THE MANUFACTURE OFPAPER.

Specification of Letters Patent No.

To all whom may concern Be it known that I, VILLIAM BISHOP,l of the townof Coventry, in the county of Tolland and State of Connecticuthaveinvented a new and useful Improvement in Machines for ManufacturingPaper, which improvement I call a Pulp Sand-Strainer; and I do herebydeclare that the following is a full, clear, and accurate description ofthe construction and operation of the same, reference being had to theannexed drawings, making a part of this specification.

Said pulp sand-strainer consists of a watertight box, represented byFigure A in the accompanying drawings, varying` in length and width,with the machine, in connection with which it is to be used, with barsfixed across the same, which bars I have usually constructed about oneinch in diameter, about one sixteenth of an inch apart, and have also soplaced as to leave a clear space between the lower'side of said bars andthe bottom of said box of about three eighths of an inch; but thediameter of said bars, and the distance at which they are placed fromeach other, and from the bottom of the box,

may be Varied at pleasure. Said bars at each end may be convenientlyinserted in a cross-piece of wood, or other material, thereby forming aframe, represented by Fig. B, which frame fits into the aforesaid box,and for the purpose of clearing the box may be removed from it, andreplaced at pleasure.

Said pulp-strainer may be constructed of wood or other substance, andshould be so placed that the pulp in traveling from the cistern to theapron of the machine will pass, or flow over and along the said strainer4,341, dated December 31, 1845.

and across the bars thereof, and also so that the fall along the samewill be as little as possible.

Fig. C represents a pulp sand-strainer, as I have constructed them, whenready to be connectedwith a paper machine.

lVhen used in connection with the Fourdrinier machine, the pulpsand-strainer may be placed either directly before or directly after theknotting screen. I have placed it after the knotting screen, in whichcase, it has taken the place of the vat -and the agitator, which arethereby dispensed with. The bars of the sand-strainer produce a ripplein the pulp as it flows across them, thereby liberating from it theparticles of sand, gravel, metallic and all heavy substances, whichthereupon fall between the bars, and settle at the bottom of the box.The pulp, by being cleared of these particles, forms a paper which iswhiter and betterboth for the purposes of writing and printing, and thecalender rolls of the machine upon which it is manufactured are savedfrom much injurious wear.

l/Vhat I claim as my invention and desire to secure by Letters Patent.is-

The mode of clearing pulp to be used in the manufacture of paper, fromsand, gravel, metallic and other hard and injurious substances by meansof the above described pulp sand-strainer. A

Hartford August 13th 1845.

WILLIAM BISHOP,

Witnesses:

WILLIAM N. MATsoN, HENRY FRANCIS,

